MySQL5.7安装

# 查询MySQL相关的依赖
rpm -qa |grep  mysql
# 如果存在, 则通过rpm -e --nodeps 进行卸载

wget  https://dev.mysql.com/get/mysql80-community-release-el7-6.noarch.rpm

rpm -ivh mysql80-community-release-el7-6.noarch.rpm

cd /etc/yum.repos.d/
mysql-community.repo: 用于指定下载哪个版本的安装包
mysql-community-source.repo: 用于指定下载哪个版本的源码

`禁用8.0的版本, 启用5.7的版本`

# 导入签名的信息key
rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022
# 安装5.7
yum install -y  mysql-community-server

systemctl  start mysqld  
systemctl status mysqld
systemctl enable mysqld

# 查看初始密码
less /var/log/mysqld.log  |grep pass

# 登录数据库
mysql -uroot -p'XRY046OefV<7'

set global validate_password_length=4;
set global validate_password_policy=0;

ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
#创建一个远程登录用户
create user 'root'@'%' identified by '123456';
# 设置远程登录权限
grant all privileges on *.* to 'root'@'%';

vi /etc/my.cnf
# 在mysqld下面设置
character_set_server=utf8

# 重启服务
systemctl restart mysqld